It isn’t.

William Morris wrote a poem called “Love Is Enough” and someone is said to have reviewed it briefly in the words, “It isn’t.”… The natural loves are not self-sufficient. Something else, at first vaguely described as “decency and common sense,” but later revealed as goodness, and finally as the whole Christian life in one particular relation, must come to the help of the mere feeling if the feeling is to be kept sweet.
To say this is not to belittle the natural loves but to indicate where their real glory lies. It is no disparagement to a garden to say that it will not fence and weed itself, nor prune its own fruit trees, nor roll and cut its own lawns. A garden is a good thing but that is not the sort of goodness it has. It will remain a garden, as distinct from a wilderness, only if someone does all these things to it. Its real glory is of quite a different kind. They very fact that it needs constant weeding and pruning bears witness to that glory. It teems with life. It glows with colour and smells like heaven and puts forward at every hour of a summer day beauties which man could never have created and could not even, on his own resources, have imagined. If you want to see the difference between its contribution and the gardener’s, put the commonest weed it grows side by side with his hoes, rakes, shears, and packet of weed killer; you have put beauty, energy, and fecundity beside dead, sterile things. Just so, our “decency and common sense” show grey and deathlike beside the geniality of love. And when the garden is in its full glory the gardener’s contributions to that glory will still have been in a sense paltry compared with those of nature. Without life springing from earth, without rain, light and heat descending from the sky, he could do nothing. When he has done all, he has merely encouraged here and discouraged there, powers and beauties that have a different source. But his share, though small, is indispensable and laborious. When God planted a garden He set a man over it and set the man under Himself. When He planted the garden of our nature and caused the flowering, fruiting loves to grow there, He set our will to “dress” them. Compared with them it is dry and cold. And unless His grace comes down, like the rain and sunshine, we shall use this tool to little purpose. But its laborious – and largely negative – services are indispensable. If they were needed when the garden was still Paradisal, how much more now when the soil has gone sour and the worst weeds seem to thrive on it best? But heaven forbid we should work in the spirit of prigs and Stoics. While we hack and prune we know very well that what we are hacking and pruning is big with a splendour and vitality which our rational will could never of itself have supplied. To liberate that splendour, to let it become fully what it is trying to be, to have tall trees instead of scrubby tangles, and sweet apples instead of crabs, is part of our purpose.